Worth building Eldigan?

He's definitely NOT fodder, at worst he's what you use until you get a better Eldigan, then you merge.

I'd run him with Mystletainn and not Dark Mystletainn, you may as well run him uniquely from Ares.

You never want to fodder a 5 star for Fury (unless you're inheriting Bartre's Hammer+ or Jagen's Silver Lance+).

I'd say build him up. He's been putting in good work on my AR teams. You could try this build if you want or go with Fury 6. He's a fine Sword Cav and a good candidate for demotion whenever that happens.

Eldigan is a strong unit, even thought there is an oversaturated pool of red horse units. He brings something different to the table that many red horses don't perform well at, being tanky. Eldigan's access to double fury makes him a powerful wall, and I slap on the Def+3 seal. Running him with bonfire makes him an excellent nuke, and coupled with his strong attack, makes him a good choice unit.